https://ntrs.nasa.gov/search.jsp?R=20170004106 2019-02-15T02:31:20+00:00Z
National Aeronautics and Space Administration
In-Space Networking On NASA’s
SCAN Testbed
Presented By: David Brooks/Vantage Partners LLC,
Cleveland, Ohio
David.E.Brooks@nasa.gov
Authors:
David E. Brooks/VPL
Wesley M. Eddy and Gilbert J. Clark III/MTI Systems
Sandra K. Johnson/NASA Glenn Research Center
www.nasa.gov
National Aeronautics and Space Administration
Agenda
Ø Motivation and Goals/Objectives
Ø Overview of SCaN Testbed
Ø Design Implementation Details
Ø Software Instrumentation
Ø Summary and Future Work
www.nasa.gov
2
National Aeronautics and Space Administration
Motivation
SGSS Requirements:
CCSDS AOS Protocols
Return AOS Frames
Forward AOS Frames
Forward Service ENCAP
Processing
Return Service ENCAP Processing
SCaN shall “provide Space
Internetworking services to mission
users” and “interoperate with
external space networks that are
compliant with space
internetworking standards.”
www.nasa.gov
3
National Aeronautics and Space Administration
Solar System Internet Implementation Challenges
Ø Requires protocol support across
mission-developed and SCaN
elements
Ø Limited number of reusable flight
or ground software components
Ø Necessary standards still under
development
SCaN Existing Network Architecture
Ø Commercial IT products do not
support space mission needs
Ø Different operations concept
between networking and legacy
point-to-point communication
services.
SCaN ~2025 Network Architecture
www.nasa.gov
National Aeronautics and Space Administration
Goals and Objectives
SCaN Testbed Networking Portfolio
Ø Gain long-term operations experience with
Space Internet
Ø Produce robust, flexible implementations for
future missions
Ø Support network topologies that represent
future mission complexity
Ø Mature the operational concept
Ø Integrate networking with realistic on-board
data interfaces
Ø Include native support for security protocols
operating across multiple layers
www.nasa.gov
National Aeronautics and Space Administration
SCaN Testbed System Overview - Architecture
TDRS-171
www.nasa.gov
National Aeronautics and Space Administration
SCaN Testbed Overview - Flight System & Initial
Capabilities
Ka-band RX
Diplexer!
TWTA
Isolator!
Ka-band TX
SpaceWire
KA HGA!
Attenuator!
SpaceWire
SN MGA!
1553
General
Dynamics S-band TX
SDR!
SpaceWire
S-band RX
Diplexer!
Flight
Computer!
Harris!
SDR!
DTE LGA!
S-band TX
1553
JPL!
SDR!
S-band RX
SN LGA!
Diplexer!
Comprehensive testing of:
• Ability to perform on-orbit
updates
• RF and physical layer
development platform
• Point-to-point physical and bit
layer services between Software
Defined Radios and Mission
Operations Center
• Command and telemetry services
SpaceWire
-
L-band RX
GPS!
Launch Software Capabilities
• Launch waveforms: Compatible with the TDRS Space Network. Limited
CCSDS Advanced Orbiting System (AOS) implemented.
• Avionics software: Focus on system control.
Launched with minimal software to meet schedule constraint
www.nasa.gov
National Aeronautics and Space Administration
Baseline Network Point to Point Links Overview
Flight
Segment
Fwd 72 Kbps
(GRC to STB)
Rtn 192 Kbps
(STB to GRC)
Fwd 18-769 Kbps
(GRC to STB)
Rtn 24-769 Kbps
(STB to GRC)
GD SN
Subnet
Ground
Segment
Flight Computer
Aitech s950
Fwd 3-3.5 Mbps
(GRC to STB)
Rtn 10.5 Mbps
(STB to GRC)
JPL SN
Subnet
Ka-Band
Harris SN
Subnet
GD DTE
Subnet
JPL DTE
Subnet
S-Band
S-Band
CCSDS
S-SN GW
CCSDS
DTE GW
CCSDS
Ka-SN GW
. Ground gateways exchange
CCSDS AOS Transfer
Frames, IP and
Encapsulation Packets with
flight gateway. IP packets
are exchange with ENCAP
Internet Protocol Extension.
Fwd 72 Kbps
(GRC to STB)
Rtn 1 Mbps
(STB to GRC)
Fwd 155 Kbps
(GRC to STB)
Rtn 192 Kbps
(STB to GRC)
DTN
(Nodes and BPSec)
Diagnostic Tools
(ping iperf eping)
Experiment
Network
IPv4
COTS Application
(firefox ftp)
Ground computer exchange
CCSDS AOS Transfer
Frames, Internet Protocol
packets and Encapsulation
Packets with the three
ground gateways.
Experimenter Machines (Linux)
www.nasa.gov
Reusable Software Components
National Aeronautics and Space Administration
Ground
Test Tools
Applications
OS Provided
Services
Flight Computer
VxWorks / PowerPC
Ground Station/ MOC
Linux / x86-64
COTS
Apps
CFDP
COTS
Apps
LTP-UDP
CFDP
TCP/UDP
BP / BPsec
ENCAP
Network Interface
for VCID/SCID TF
(Kernel Module)
User space
AOS TF
Injection app
LTP-UDP
IPv4/IPv6
IPE
IPsec
LTP
ENCAP
IPv4/IPv6
LTP
ENCAP
AOS
PRIV
Space Network
AOS
PHY Link Sync
Serial to User
space AOS TFs
(Kernel Module)
ENCAP to
MUX Kernel
Module
IPsec
TCP/UDP
IPE
Service
Loopback
BP / BPsec
EPING
VxWorks
Application
ports: ION,
ping, httpd,
iperf
SYNC & CODING
RF
SDR / FPGA
SYNC & CODING
RF
PRIV
AOS-ENCAP
Convergenc
e Tasks
TDRSScompatible
waveform
www.nasa.gov
Software Instrumentation
National Aeronautics and Space Administration
Experiment
Front End
Processor
CCSDS
GW
Flight
Computer
SN Statistics
GRC GS
• Loggable CCSDS Statistics (ENCAP
and AOS) in user space
• CCSDS ENCAP capture using COTS
libpcap and tcpdump
• eping test application for ENCAP
RTT and link errors
GS Statistics
Tracking
Power Levels
Modem (TSIM)
•
•
•
•
FS and SDRs
Physical Link
Tracking
Health and Status
Waveform Status
(Primary Path)
Encapsulation Packet Statistic
@CCSDS GW:
•Number Received/Sent through GW
•Number of various Errors such as bad
length, invalid ENCAP header, etc..
=>Readable in user space as a file
Data
Flow
Experimenter
Machine
• ICMP “ping” for RTT
• Ethernet packet capture
• ION Applications
Synchronous Serial AOS
Statistics@CCSDS GW:
•Number AOS TFs Received/Sent
through GW
•Various Errors such as bad length,
dropped frames
=>Readable in user space as a file
Physical
Layer
Networking/Flight
SPW and ENCAP Stats
(Primary Path APID)
Experiment Path Stats
(currently work/NITRO)
www.nasa.gov
National Aeronautics and Space Administration
Conclusion and Future Work
• SCaN Testbed networking implementation and
knowledge gained will enable NASA’s transition to
Solar System Internet. This include demonstrating
IPv4 routing on a CCSDS reusable ground and flight
software components that served to:
– Produce a robust, flexible implementations for future
missions
– Create a baseline topology with CCSDS that integrates with
future complex missions
– Help to mature the operational concept by integrating CCSDS
with a space testbed
– Integrate networking with realistic space on-board data
interfaces (Spacewire)
– Include native support for security protocols operating across
multiple layers (Secure DTN)
www.nasa.gov
National Aeronautics and Space Administration
Conclusion and Future Work
• Foundation has been laid for cognitive networking
capabilities research and development activities
such as NASA Intelligent Routing(NITRO),
Cognitive Networking(COGENT) and SCaN Testbed
that evolves to Cognitive Communication project
www.nasa.gov
National Aeronautics and Space Administration
Space Protocol Research on the SCaN Testbed
CCSDS 734.2-R-3
CCSDS Bundle Protocol
Specification
Application
Transport
Network
Data
Link
Network Management Protocol
Key Distribution Protocol
Bundle Protocol Security (BPsec)
CCSDS 727.0-B-4
CCSDS File Delivery Protocol
CCSDS 702.1-B-1
IP over CCSDS
Space Links
CCSDS 734.1-B-1
(LTP)
CCSDS 133.1-B-2
Encapsulation Service
CCSDS 131.0-B-2
TM Synchronization
and Channel Coding
CCSDS 131.3-B-1 CCSDS
Space Link Protocols over
ETSI DVB-S2 Standard.
CCSDS 732.0-B-2 AOS Space Data
Link Protocol
CCSDS 131.5-M-1 Variable Coded
Modulation Protocol
Physical
CCSDS 401.0-B-25
RF Earth Stations
and Spacecraft
Cross
Support
SLE
CCSDS 911.1-B-3
Space Link
Extension—Return All
Frames
CCSDS 911.2-B-2
CCSDS 911.5-B-2
CCSDS 415.1-B01
Data Transmission and PN Ranging for 2 GHz Link
via Data Relay Satellite
CCSDS 912.11-0-1
SLE–Enhanced
Forward CLTU
CCSDS 912.1-B-3
SLE–Forward CLTU Svc
CCSDS 913.1-B-1
SLE – IP for Transfer Svc
SCaN Testbed
on ISS
www.nasa.gov
National Aeronautics and Space Administration
AOS and ENCAP on SCaN Testbed
www.nasa.gov
National Aeronautics and Space Administration
Acronym List
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
AOS – Advanced Orbiting Systems
BP– Bundle Protocol
CCSDS – Consultative Committee for Space
Data Systems
CSO – Communication Service Office
DSE – Deep Space Element
DTE – Direct to Earth
DTN – Delay Tolerant Networking
EBRE – Earth-Based Relay Element
ENCAP – Encapsulation
Fwd – Forward service
GRC – NASA’s Glenn Research Center
GS – Ground Station
GW – Gateway
ION – Interplanetary Overlay Network
ISS – International Space Station
LTP – Licklider Transport Protocol
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
LTP – Liklikder Transport Protocol
NASA – National Aeronautics and Space
Administration
NEE – Near Earth Element
NISN – NASA Integrated Services Network
NITRO – NASA Intelligent Routing
OS – Operating System
Rtn – Return service
RTT – Round Trip Time
SCaN – Space Communication and Navigation
SGSS – Space Network Ground Segment
Sustainment
SN – Space Network
SPW – SpaceWire
STB – SCaN Testbed
TDRS – Tracking and Data Relay Satellite
TSIM – TDRS Simulator
TF – Transfer Frame
www.nasa.gov